Specialist teams, auto manufacturers and others: The folks who make the cars

Specialist teams such as McLaren and Williams build the cars and run the whole enterprise. They have the premises, facilities, and staff that design and build the machines. Major car manufacturers such as Honda, BMW, and Mercedes are also involved in Formula One � but as engine suppliers. The manufacturers usually go into partnership with a team so that, for example, Honda supplies engines to BAR, while BMW motors power the Williams cars. There are exceptions, though. Ferrari has always produced its own engines, as well as chassis, and Ferrari�s recent success has some people thinking that there may be something in this. Upon its entry into Formula One in 2002, Japanese car manufacturer Toyota decided to go the Ferrari route, establishing a manufacturing base in Cologne, Germany, that designs and builds both chassis and engines.
Ferrari and Toyota also build their own transmissions. Most of the others buy components from a specialist racing gearbox manufacturer, though often to their own design.
Increasingly, no set rule governs who makes what. The car manufacturer Renault, for example, bought the former specialist team Benetton outright and uses its British base and staff to design and build the chassis, but the engines are still produced in France. Jaguar Racing is owned by Ford, with engines supplied by Cosworth � another Ford offshoot. DaimlerChrysler (manufacturers of Mercedes-Benz) has an equity stake in the McLaren team and in the specialist engine manufacturer Ilmor which builds the Formula One engines bearing the Mercedes badge that are fitted into the McLarens. Regardless of who makes the stuff, a Formula One car represents a stunning feat of technology, engineering and design.

Two cars in one: The car that races and the car that qualifies

From the 2003 season Formula One cars have to race just as they qualified on Saturday; no set-up work or additional fuel is allowed in between. But the running order on the track during Saturday qualifying is determined by Friday qualifying, and no restrictions exist on what can be changed between these two days.
As you can imagine, a car that has to do just one flying lap on Friday has different specifications than a car that has to both qualify on Saturday and race on Sunday. On Friday, the speed over one lap is the prime consideration. For that reason, everything is pared down as much as possible. Thinner brake discs are fitted (they don�t have to last a race distance), and the bodywork, which must be more aerodynamically efficient, includes fewer concessions to engine and brake cooling. The biggest difference, however, is the set-up of the cars: On Friday, the suspension settings are optimised for speed over one lap. Such a set-up on race day would quickly destroy the tyres. Similarly, the wing settings are higher than in the race, when speed down the straight is important in order to be able to pass other cars, even if it means sacrificing some cornering grip.

F1 Ballast: Putting on a few pounds

A Formula One car has to weigh no less than 605kg, including the driver and his helmet. But the cars are actually built far lighter than that. Ballast is then used to bring the cars up to the regulation weight. The ballast is placed so that it gives the best possible weight distribution for optimum handling and tyre use. Therefore, the lighter the car can be made, the more the team can vary the car�s weight distribution to suit the track and the driver�s preference.
The lightest of the current cars pre-ballast and without driver � 60�75kg � is believed to be around 410kg. The ballast is normally made from tungsten and is mounted on the lowest point of the car�s underbody in order to keep the centre of gravity down.

F1 Electronics: The car�s brains

Electronics control engine, transmission, and chassis systems. Just as in a modern road car, an ECU (electronic control unit) determines the Formula One engine�s optimum fuel and ignition settings based on thousands of measurements each second taken by dozens of sensors and controlled by thousands of parameters. Electronic radio signals have replaced cables and linkages to give a �drive-by-wire� system similar to those used in modern aircraft. The throttle, for example, has no linkage between the pedal and the fuel supply other than an electronic one. Electronics, in conjunction with a hydraulic system, also control when the car changes gear, based upon what the engine is doing. The differential � the mechanical device that determines how the power is split between the rear wheels � is controlled electro-hydraulically, too. But perhaps the most controversial use of electronics is that for traction control. Based on measurements of wheelspin and engine torque, a computer limits power to the rear wheels in order to make the car faster and easier to control. These are Formula One drivers, you say, and should be able to control traction themselves? You�ve got a good point, and the drivers can do it themselves, but the computer does it better. Charges of this de-humanising the sport are difficult to argue with. The problem has been getting detection techniques sophisticated enough to control the use of traction control. It�s the age-old story of those designing the cars being cleverer than those making the rules.

F1 Built-in safety features

A Formula One car also has built-in safety features. Within the cockpit surround is a padded area designed to protect the driver�s head during an impact. A sixpoint harness, with straps that go around the driver�s shoulders, legs, and groin and meet in a single quick-release mechanism, is also built in. Since 2003 the wearing of the HANS (head and shoulder support) device has been mandatory. The HANS device, shown in Figure 5-5, prevents a driver�s head from being thrown forward or sideways in an impact � a classic cause of neck and spinal injuries in accidents.
To help drivers get out from what is an extremely confined space, the steering wheels are also removable. Before a driver is cleared to drive, he must be able to evacuate the car and then replace the steering wheel (to aid marshals moving the car from a dangerous position) within 10 seconds. Proving that he can do it once isn�t enough. Drivers are regularly asked to perform this manoeuvre to prove that they can.

Inside the F1 cockpit

Every bit of a Formula One cockpit not occupied by the driver is crammed tight with technology.

• Buttons: The carbon fibre steering wheel houses controls for the communication radio, the setting of the differential (to change handling characteristics), the fuel mapping (to change the power/economy compromise), the pit lane speed limiter, and the traction and launch control.
• Controls: Behind the steering wheel are controls for the clutch � needed only to get the car moving when launch control isn�t being used � and the gear change. The driver uses a flipper switch on one side of the wheel to make downchanges and one on the other side of the wheel to make upchanges. Normally the gear changes are made automatically � making these controls redundant � but in some situations, a driver may prefer to change gears manually or may be forced to because of technical glitches.
• Instruments: In terms of instrumentation, the cockpit display is quite bare. Small digital read-outs tell the driver engine revs, engine temperatures, minimum corner speeds, and instant lap times.
• Pedals: The cars have only two pedals: a throttle on the right and brake on the left. Most Formula One drivers brake with their left foot.
• Seat: The driver�s seat is moulded to his own particular shape.

Slick tyres: Why they aren�t used in Formula One

Between 1971 and 1997, Formula One cars used to race on slick tyres � that is, tyres with no tread at all. This lack of tread gave the maximum surface area of rubber on the road, thereby maximising dry weather grip. Most other racing categories still use slick tyres but, since 1998, they�ve been outlawed in Formula One and replaced by the regulatory grooved tyre. The governing body made this change purely to limit the performance of the cars, for reasons of safety. Tyre engineers estimate that slick tyres would make Formula One cars around 3 seconds per lap faster than they currently are.

Understanding F1 tyres

As the cars� only contact area with the track surface, tyres obviously play an enormously important role in the performance of the machines. So critical, in fact, that the sport�s governing body invariably uses limitations on the specification of the tyres as the key way of controlling the performance of the cars. The limits for dry-weather tyres are currently those of width and tread groove.

• Width: The front tyres must be between 12 and 15 inches (305�381mm) and the rear tyres between 14 and 15 inches (356�381mm). The back tyres can be wider than the front because the back has more work to do. The weight distribution of the car is rearward-biased, because that�s where most of the mechanical components are. Furthermore, the rear tyres are transferring the engine�s power to the road.
• Tread groove: Four grooves must run through the circumference of the tyre. The shape and depth of these grooves is also specified by the regulations. The regulations for a wet tyre specify contact area rather than tread pattern or shape.

Formula One tyres grip the track far better than those of any road car could, but this performance comes at the expense of durability. However, a set of tyres on a Formula One car does not need to last any more than the length of a race and more often than not, even less.
Both grip and durability are largely determined by a tyre�s compound, the complex mix of the constituent chemical parts that comprise the material the tyre�s made from. The softer the compound, the better gripping but less durable the tyre. Different circuits place different demands on a tyre, according to the nature of the track surface and the design of the course. Tyre manufacturers come up with compounds tailor-made to each track. The other critical aspect of a tyre�s design is its construction, the way in which its carcass is designed. The stiffer the construction, the greater the load the tyre can withstand and, therefore, the softer the compound can be. A Formula One tyre is very temperature-sensitive. It has virtually no grip at all below its designed operating temperature and would therefore be lethally dangerous if used on the road. Getting the tyre up to temperature requires braking and cornering hard enough that only an accomplished racing driver is able to do it.

The braking news

Much of the staggering braking performance of a Formula One car is a result of the enormous download from its wings and other aerodynamic features pressing the car into the ground. This download makes the tyres able to withstand such big braking forces. But the brakes themselves need to be able to fully exploit this force. The key to this exploitation in recent years has been the advent of carbon fibre brake discs and pads.
Carbon fibre discs operate at a temperature range of between 500�800 degrees centigrade. Below that range, the discs are fairly ineffective; above it, they begin to oxidise, that is, they begin shedding their mass in a process very similar to the rusting of metal, albeit faster. Keeping the brakes within this temperature range is a key part to a car�s performance, especially because of the regulation that limits the thickness of a disc to 28mm. (This regulation was introduced to keep a check on braking performance so that overtaking didn�t become impossible.)
The braking forces are the most impressive facet of a Formula One car�s performance. Whilst the best road cars might generate up to 1.5g (g is the force of gravity, so 1.5 times the force of gravity) under extreme braking, a Formula One car can pull over 4.5g. This level of force actually affects the blood flow to the driver�s eyes, and some drivers have noted a momentary effect on their vision. Others have commented on how tears in their eyes get thrown onto the inside of their visors. Such is the downforce and engine compression of the cars that just lifting off the accelerator pedal generates 1g � about the same as a full ABS emergency stop in an average road car. That�s before you have even touched the brake pedal!

Using the suspension to set up F1 car

A Formula One car is almost infinitely adjustable so that it handles according to the demands of the track, conditions, and the driver. The set-up of a car refers to particular settings: wing settings and suspension. The necessary balance between cornering downforce and straight line speed is determined by wing settings (see the section �Wings and underbodies�, earlier in the chapter). But this is only part of the set-up. The more complex part is that of suspension.
In general, the suspension set-up is determined by balancing two aims which are frequently at odds with each other: the need to adequately support the cornering and braking force of the car and the need to achieve the necessary responsiveness of handling. A circuit generating high aerodynamic loadings, for example, generally demands stiffer springing, but this can cause problems in slower corners where the suspension needs to be more supple in order to enable the car to brake well and to ensure good direction-changing response to the wheel. Achieving a good set-up invariably involves finding the best compromise. Achieving maximum grip is obviously important, but getting the best handling balance is even more so.
Driven to its limit, any car will surrender its grip at either the front or the back. There is no such thing as a car with unlimited grip, and any racer worth his salt soon finds where the limit of grip is. This is where the handling balance takes over. Handling balance refers to whether the car runs out of grip at the front first and understeers (that is, tries to run straight-on when asked to turn) or surrenders grip at the rear first and oversteers (turns more than asked). A very narrow window of neutrality exists between these two states, where both ends of the car surrender their grip at the same time, and the car drifts, but this state is rarely seen with modern cars. Driver preferences and the timing monitors determine the best handling balance for a given car and track at a given time. In terms of wing settings, oversteer can be tamed by using more rear wing or less front. Understeer would be countered by more front wing or less rear. But playing with wings is the easy � and usually less efficient � way out of a handling imbalance, because it involves screwing up the ideal downforce/straight line speed trade-off So for a given wing set-up, the handling is usually fine-tuned with the suspension. The suspension components that are used to determine handling balance are the following:

• Springs: A spring that�s not stiff enough under cornering doesn�t properly counteract the car�s tendency to roll, moving its centre of gravity outwards and quickly overwhelming the outer tyre�s ability to keep a grip on the road. A spring that�s too stiff slows the transfer of load from the inner to the outer tyre too much; as a result, the outer tyre isn�t being loaded enough to achieve its potential before the corner is over. However, the spring rate that�s just right for one corner on the track may be wrong for the next one, because of the corners different shape and speed. To further complicate matters, the difference front to rear must be considered as well. If the spring rate at the rear is just right, both toostiff or too-soft at the front produces understeer. If the front rate was just right, both too-stiff or too-soft at the rear produces oversteer. The driver and his engineer need to find a compromise over the many and varied corners of the track; this compromise may involve surrendering some grip from one end of the car to get the desired balance. At circuits with a wide variation of corners, variable rate springing may be used to give a relatively soft spring at low speeds but a stiffer one at high speeds.
  
• Dampers: Dampers don�t determine a car�s grip as much as they determine how much of the grip the driver can access. The dampers offer a very effective way for drivers to fine-tune the car�s handling in the limited time of a practice session. The damper is adjustable in the bump phase of its progression (as it absorbs the initial bump) and in the rebound phase. These adjustments can be made in two ranges � low speed and high � to give four-way adjustment. The damper is also adjustable within the overall range of frequencies in which it works, although this involves fitting different internal valves � not normally something done during practice. A driver might soften the bump rate if the car�s trajectory is being affected by bumps in the braking or cornering zones or if he wants to use more kerb without being thrown off line. Softening the damper�s bump rate allows the spring to smother more of the bump�s effect. A driver may increase the damper�s rebound setting in order to keep the nose of the car down after he has finished braking to help him get the car turned into the corner. In addition dampers include �blow-off valves�. These valves enable the damper to ignore any out-of-range inputs so that, for example, a severe kerb can go undamped beyond a certain range and so not compromise the settings needed on the rest of the track.
• Arms: The linkage formed by the suspension arms and how they interact front to rear have a direct bearing on the overall handling characteristics of the car. The geometry of the wishbone linkages determine the roll centre of the car. The roll centre is an imaginary, but accurately defined, point on the centre-line of the car around which the car rolls on its suspension. The roll centre can be high off the ground, low, or even underneath the ground (it�s only imaginary, remember). A line connecting the rear suspension roll centre with that of the front is called the roll axis. If the axis runs nose-down, the car tends to oversteer. If the axis runs nose-up, the car tends to understeer. These linkages are intrinsic to the car�s design and can�t be changed during a race weekend, but some adjustment can be made to the car�s ride height (the height above the ground of the car�s underside) via the suspension�s pushrod. The closer to the ground, the more grip but the less the car can tolerate bumps and kerbs. The camber of the wheels can be altered by adjusting the wishbones so that the highly-loaded outer wheel becomes upright under cornering and uses more of the tyre�s width rather than just the outer edge. (Here, camber refers to when the wheels aren�t perfectly upright, but run at an angle to the road surface, usually with the bottom pointing in slightly.) The downside of altering the camber is that it makes the car less good under braking.
• Roll bars: Roll bars have a big effect on the car�s handling, particularly in the first part of a corner as the driver turns in. The bar�s primary function is to keep roll under control, but the way it does this also results in cornering load being transferred from the inner tyre to the alreadyloaded outer tyre. If the spring rates aren�t too stiff, this detracts from ultimate grip. Taking grip away from the front or the rear by increasing the stiffness of the roll bar gives the driver another tool in adjusting the car�s handling balance.

Formula One suspension components

The suspension is made up of the following components:

• Springs: The springs absorb the basic loadings. Sometimes these are in the classic coil shape that most people associate with the word spring. More usually, however, they are things called torsion bars, a sort of straightened-out spring, that makes for easier changing and lighter weight. Changing the stiffness of the spring � how much it deflects for a given load � is a key way to change the handling of the car.
• Dampers: Once a load is released from a spring � like when the car has finished cornering or braking � the spring oscillates. Dampers damp out the oscillations, enabling the car to recover its equilibrium quicker. The stiffness of the dampers is adjustable, and they form another key variable in establishing the driver�s preferred set-up.
• Arms: Arms are the connections that transfer the loadings from the wheels to the spring/dampers. In a Formula One car, arms are almost always arranged in what is known as the double wishbone formation. Two upper and two lower arms stretch horizontally in a vee shape from the wheel to pick-up points on the chassis. In between is a pushrod, a single arm that stretches (at an angle from the horizontal) from the wheel to the spring/damper attached within the main chassis. As the wheel moves up and down supported by the wishbones, the pushrod translates the loadings onto the spring and damper. The arms are connected to the wheel via an upright, a cast piece of metal (usually titanium) onto which the wheel hub is bolted on one side and the suspension arms on the other. The front suspension arms (and sometimes the rear suspension arms, too) are usually made from carbon fibre. But the heat from the exhausts can have a damaging effect on the strength of the material, requiring that an exotic lightweight metal might be used instead.
• Roll bars: The roll bar is a metal bar linking one side of the suspension to the other. It limits how much the car rolls during cornering. The thickness of the bar determines its stiffness. There is a roll bar at the front and another at the back of the car.

Formula One suspension

Suspension is demanded by the technical regulations. Technically, a Formula One car could get by without it � it would be like a big go-kart � but the drivers� spines would take damaging punishment. The role of suspension in a Formula One car isn�t just to give the driver a smoother ride though. It is also a vital tool in adjusting the handling of the car to suit individual circuits, track conditions, or driver preference.
The suspension needs to be compliant enough to allow the driver to shave vital hundredths of a second from his lap time by cutting across kerbs, but it also must be stiff enough to withstand the huge aerodynamic loads that press the car down to the track surface. Sounds like a near-impossible demand? Hey, if it was easy, we�d be out there doing it!

End plates and barge boards

Getting the air to separate cleanly between upper- and under-body is vitally important to the effectiveness of the aerodynamics. Endplates, the complex shapes at the sides of the front wing, are designed to do this. Further back, low on the side of the bodywork, behind the front wheels, are the barge boards. Barge boards pull the air coming over the front wing along more quickly � and thus increasing the downforce � and then channel it where needed.

Understanding Formula One Diffuser

Wings work the air that passes over the car�s body. But air travelling beneath the car is also harnessed. The regulations state that the underbody of the car must be flat up to the rear wheel axle line, but, from that location to the rear extremities of the car, anything goes. This rule has allowed designers to incorporate an upward-sweeping device, called a diffuser, beneath the engine and gearbox. The diffuser�s shape causes air to be sucked into its narrow opening which then opens out into a bigger area. Air fed through a shape such as this creates a pressure change that induces a suction effect.

Understanding Formula One Wings

The most visually obvious of the car�s aerodynamic features are the front and rear wings affixed onto the car�s chassis. These wings work on a principle similar to that used on aircraft wings � except Formula One wings are upsidedown and provide downforce instead of lift. If air passes a longer distance over the lower surface of an object than an upper one, it creates a downward pressure. The wings are shaped so as to create this effect, pressing the tyres into the ground.
In increasing downforce the wings also create a lot of air resistance, slowing the car in a straight line (a Formula One car without wings would be able to reach around 300 mph rather than the 220 mph it can currently reach). If the wings could be lowered into the body of the car until they were needed, you would see a big performance gain. But moveable aerodynamic devices are banned and have been since 1969. The angle of the wings can be set to varying levels of effectiveness, and changing the balance between front and rear downforce is a key way of adjusting the handling of a car.

Getting into gear: The transmission

The engine�s power is fed to the rear wheels via a gearbox. This gearbox must have a minimum of four forward gears and a maximum of seven gears (although everyone opts for either six- or seven-speeds). A reverse gear must be fitted. The gearbox is connected to a differential � a mechanical device that determines how the power is split between the inner and outer wheels. Driveshafts take the power from the differential to the wheels. These principles are exactly as in almost every car in the world. But the detail is very different.

Although the system of cogs and shafts are like a conventional manual gearbox, the gears are selected not by a conventional mechanical linkage but by hydraulic pressure actuated by electronic control. Although the driver can change the gears, usually the gears are selected automatically, controlled by the electronic brain of the engine. This system saves time (electronically controlled shifts take less time than manual shifts), increases safety (the driver can have both hands on the wheel at all times), and helps the car aerodynamically (the cockpit can be narrower because it doesn�t have to include a gear lever). A very fast manual upchange using the old mechanical system used to take around 0.1 seconds, during which time the car would lose about 2 mph because of the high aerodynamic drag and engine compression of the car. The electronically controlled shifts take only around 0.02 seconds.

The differentials can be tuned to alter the handling characteristics of the car. These too are electro-hydraulically controlled and have sensors measuring the torque being fed to each driveshaft. The traction control system, which cuts the power when wheelspin is detected

How thirsty is a Formula One engine?

We can take it as read that the drivers use their engines to the max (if not, then they�ll soon be out of Formula One employment). But, within this accepted premise that drivers push their engines to the limit, the fuel mileage of a Formula One car can still vary considerably. What kind of mileage a Formula One car gets depends upon a couple of things:

• The nature of the track: A track that requires a lot of braking from high speed down to slow � and lots of accelerations back up again � makes the cars consume more fuel than does a track with a more flowing nature, where speeds are more constant. Also tracks with lots of corners make the cars run more downforce through altering the settings of their wings. This costs aerodynamic drag on the straight, and that hurts fuel consumption.
• The engine settings: The team can alter the fuel/ignition settings from the pits via telemetry. Sometimes they do this to help a driver eke out an extra lap or so before a pit stop; sometimes they make changes just to play it safe when a driver�s race position is under no threat.

Given these qualifications, we can say that the fuel consumption of a Formula One car typically varies from around 3.5 mpg (miles per gallon) up to around 4.3 mpg.

Building a Formula One �tub�

Once the engine and chassis designers have agreed upon a general specification and outline of the chassis, 3-D computer-aided drawings (CAD) are made. The same raw data that produced the drawings is then used for computeraided manufacture (CAM). Before the carbon fibre tub is constructed, mirror-image moulds are made, and before that can be done, patterns need to be built to form the moulds. Blank slabs of a man-made material called Ureol are typically used for this. These slabs are machined into the required forms, directed by the CADCAM information.
The various patterns bolted together form a dummy Formula One tub, complete with nose cone. A scanner goes over this, taking measurements, which are compared to the original CAD drawing for accuracy. The dry sheets of carbon fibre are laid out over the pattern. A resin is impregnated within them. This resin releases and bonds under the pressure and temperature of an autoclave, thereby holding the whole thing together in the required shape. Holes and recesses are introduced into the moulds by tooling blocks that replicate suspension and engine mounting points.
With the moulds completed, the carbon fibre is laid up over them, but in a much more complex formation than was used to create the moulds. A calculation technique called finite stress analysis will have shown the engineers where the strength needs to be and so extra layers are laid in at the appropriate places.
Multiple layers mean several stints in the autoclave before the final high-pressure, high-temperature run of around 2.5 hours. Bonded together, the final tub weighs around 30kg.

Understanding F1 Engine

A Formula One engine operates on the same basic principle as any old petroleum-fired motor. It�s an internal combustion engine, with a cylinder block, cylinders, pistons and valves. The pistons inside the cylinders move up and down, driven by an explosive combustion of fuel and air allowed in by the inlet valves. The spent gases are allowed to escape via the exhaust valves. The pistons connect to a crankshaft which in turn drives camshafts � and those are the things that open and close those valves. Nothing new there. The radical thing about a Formula One engine is its light weight and humungous horsepower. Reconciling almost 900 horsepower with something that weighs less than 90kg may seem impossible, but a Formula One engine does so.

The engine uses very exotic metals � and some non-metallic materials too �to keep its weight and heat expansion down. A Formula One engine relies on speed to get much of its power, with the best of the current engines running to almost 19,000 revs per minute (rpm), about double the speed of the highestrevving road cars. How is that possible? Well, the engines have to be rebuilt after around 500 miles � kind of expensive. Any engine can be squeezed for more revs and power if it only has to last such a short distance. Current regulations limit the engine size to 3000cc (cubic centimetres), and turbo, or supercharging, is prohibited. The engine must have 10 cylinders. Four pneumatically-operated valves � two inlet and two exhaust � feed each cylinder (although up to five are allowed, no-one has found an advantage from this).

The pneumatic operation gives greater accuracy at high speeds than conventional valve springs. The cylinders are arranged in two banks of five, the banks splayed at an angle to each other to form a vee, hence the term of �V10� in describing the layout of the engines.
Why 10 cylinders and not less or not more? The pros and cons are as follows:

• Engine speeds: The greater the number of cylinders an engine has, the more power it can theoretically produce. For a given engine capacity, each cylinder will be smaller the more of them there are; for example, each cylinder in an eight-cylinder, 3-litre engine would be of 375cc whereas a cylinder in a 10-cylinder 3-litre would be only 300cc. The smaller pistons inside these smaller cylinders can be moved up and down the cylinders faster. The faster they move, the more power they produce.
• Valve area: Having more cylinders means greater inlet and exhaust valve area, which in turn means that more fuel and air can be pumped through the engine. That translates to more power.
• Heat expansion: With more cylinders, less energy is lost to heat expansion because smaller cylinders and pistons can disperse their heat easier. Again, this means more power. On the other hand, higher speeds from more pistons mean more heat is generated. Complex, isn�t it?
• Frictional losses: These refer to the energy you lose through the friction of one surface against another (in this case, a piston within a cylinder). The more cylinders, the more frictional losses.
• Weight: The more cylinders, the more weight because not only does the engine have to be physically longer to fit in all those cylinders, but each cylinder brings its associated pistons, valves, connecting rods, and so on.
• Fuel economy: Spreading the engine�s explosions between 10 cylinders rather than 8 is less fuel-efficient, so with more cylinders comes the need to carry more fuel, making the car yet heavier.

Many years of experience established that 10 cylinders was the optimum trade-off between these opposing pulls. As materials technology advanced, however, a real possibility existed that the optimum trade-off might have moved onto 12 cylinders or more (as many as 16 have been used in Formula One in the past). To close down an area of future expense, the governing body nailed the limit as 10 back in 1999.

The angle between the vee of cylinders is an area of key concern � and not just to the engine designer, but for the chassis designers too. The wider the angle is, the lower the car�s centre of gravity becomes, to the advantage of its grip and handling. But if the angle is too wide, the engine starts to block up the airflow around the back of the car, which leads to less efficient aerodynamics. Certain vee angles introduce bad vibrations that limit engine speeds and, therefore, power. At the moment, 90 degrees is the favourite trade-off between these conflicting pulls, though there are some shallower and one wider than that.

You might assume that power is everything and that an engine�s fuel consumption can go and be damned. But you�d be only partly right. Power and light weight are primary goals. But, within those requirements, the better an engine designer can make the fuel mileage, the less fuel in the tanks at the start of a race. Less fuel makes the car lighter � and therefore faster � and also keeps the fuel tank size down, to the benefit of the car�s aerodynamics.

Understanding F1 chassis

The chassis is the central structure of the car, the part that the engine and suspension are bolted on to and the part that the driver sits inside. It�s usually referred to as the tub because that�s what it looks like before you bolt all the stuff onto it.
Formed from carbon fibre, the chassis has to be strong to withstand repeated downforce loadings (the weight pressing down on the car as a result of the airflow over it) of over 2,000kg, yet it weighs only around 30kg. If the chassis were insufficiently stiff, the car wouldn�t be able to translate the aerodynamic loadings to the tyres. Stiffness combined with low weight � two conflicting requirements � are the keys to a good chassis. The chassis is manufactured by laying up sheets of carbon fibre with a bonding agent in the shape required via a mould. This is then �cooked� in an autoclave (think of it as a big oven). You may think that a Formula One driver would rather not trust his life to something that sounded like it had been put together more like a cake than a car. An understandable concern, but you�d be wrong. The material provides much more protection in a big impact than the aluminium from which a Formula One chassis used to be made. Stress analysis tells the structural engineers precisely where the strength needs to be in the chassis, and so extra layers are incorporated at key points, such as suspension mounts. Getting the necessary stiffness is extremely difficult when the structure has to include one great big hole for the driver to sit in and another one for the fuel tank. But the engineers manage it; that�s what they�re paid the big bucks for.
Technical regulations require the chassis to have a flat floor (so limiting the amount of aerodynamically-induced grip). Regulations also specify minimum cockpit dimensions and minimum space requirement for fuel tank size (which is driven by how many laps the car needs to do on those tracks that induce the heaviest fuel consumption). Within those constraints, the chassis has to be as compact as possible to keep its frontal area, and therefore its air resistance, down.